The above-referenced related application discloses a method and means for increasing the servo sector sampling rate in a disk formatted in a fixed block architecture (FBA), such increase being effected with a minimal increase in the overhead (non-data) regions. The disk has the prior art conventional servo sectors which contain all servo and associated overhead information. However, micro servo sectors are inserted in the data fields between the conventional servo sectors to provide short bursts of servo information. These micro servo sectors contain a small portion of the overhead information, only sufficient to provide position information and to control the temporary interruption and restoration of the write current and the data stream and clock input to a data encoder/decoder. Because the servo bursts are short, no resynchronization of the VCO is necessary after each burst. These micro sector bursts are used only during settling (since they contain only position error signal data) and also preferably during seek (if an abbreviated Gray code is used); and the conventional sector servo bursts are used during read and write track following. This technique desirably provides high sample rates with minimal overhead in disk files using a sectored servo system, such as used in low end disk files with FBA format.
Several techniques, now becoming increasingly popular to increase the areal density in sectored disk files, are constant linear density (CLD) recording and banded recording. In CLD recording, the data rate for a given track depends upon its radius. Banded recording is somewhat similar, except that the data rate is constant within a given band of radii, but varies from band to band to minimize the range of linear densities. It follows, then, that if implemented in sectored servo, the number of sectors and hence of servo samples would increase progressively from the innermost to the outermost bands, and thus require the servo system to adjust to the differing sample rates. Also, seeks across bands and settles at band edges would require constant updating of the sample rate, and timing of the servo samples would vary.
There is a need for a recording technique, transparent to the user, useful for both non-sectored and sectored disk and tape formats, wherein servo sample rate is constant and is independent of the data architecture used and limited only by the total area of the disk devoted to servo information.